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ARGENTINA | 04-05-2022 08:00

'Death shadow' dinosaur unearthed by palaeontologists in southern Argentina

Argentine palaeontologists announce discovery of 'Maip macrothorax,' an apex-predator dinosaur and the largest megaraptor unearthed to date.

Argentine palaeontologists have announced the discovery of an apex-predator dinosaur that measured three storeys from nose to tail and eviscerated its prey with sharp, curved claws. 

The six-ton giant stretching more than nine metres, the largest megaraptor unearthed to date, fed on smaller dinosaurs that it ripped to shreds with its talons before digging into their intestines, palaeontologist Mauro Aranciaga told AFP.

It would have been the "apex predator" of its time, said Aranciaga – well deserving of its chilling scientific name "Maip macrothorax."

The first part, "Maip," is derived from an "evil" mythological figure of Patagonia's indigenous Aonikenk people.

The character was associated with "the shadow of the death" that "kills with cold wind" in the Andes mountains, according to a study reporting the find in the Nature journal Scientific Reports.

The second part, "macrothorax," refers to the enormous expanse of the creature's chest cavity – some 1.2 metres (3.9 feet) wide.

The first fossils of the dinosaur were found in an area known as Estancia La Anita, some 30 kilometres south of the tourist city of El Calafate and close to the famous Perito Moreno glacier in the southern province of Santa Cruz.

'Childhood dream'

The newly-identified monster measured nine to 10 metres in length, larger than any previously discovered type of megaraptor – a group of flesh-eating giants that once roamed what is now South America, according to Aranciaga's team.

“It is a very big, very heavy animal,” said the expert.
It lived about 70 million years ago towards the end of the Cretaceous period in what was then a tropical forest, long before the Andes mountain range and glaciers that now define Patagonia.

The killer reptile had two sharp, curved claws per front paw, each talon some 40 centimetres (15.7 inches) long.

Aranciaga, now 29, had the good fortune of finding the first piece of Maip on his first-ever professional expedition three years ago to Santa Cruz Province.

This led to months of meticulous digging, cleaning and classification of a large cache of bones: vertebrae as well as bits of rib, hip, tail and arm.

"When I lifted the vertebra and saw that it had the characteristics of a megaraptor, it was really a huge thrill," recalled Aranciaga.

"Somehow I fulfilled my childhood dream... finding a new fossil and it turning out to be a megaraptor: the group in which I specialise," he told AFP.

Maip was one of the last megaraptors to inhabit Earth before the dinosaurs went extinct about 66 million years ago, according to Fernando Novas, head of the Laboratory of Comparative Anatomy at the Bernardino Rivadavia Argentine Museum of Natural Sciences.

Novas discovered the first megaraptor in 1996 in Neuquén Province, some 1,400 kilometres north of the current find. Others were later found in Australia, Thailand and Japan.

‘Extraordinary deposit’

Maip is the southernmost megaraptor ever found, explained Aranciaga, a doctoral fellow at Argentina's National Scientific and Technical Research Council (CONICET).

It was found at "an extraordinary site that is proving to be one of the most important we have in South America,” he explained, adding that it is from the Cretaceous period "when there was no Andes mountain range or glaciers, but there were tropical forests where an enormous diversity of beings lived.”

"In these rocks there are fossils of very diverse organisms: snails, fish, frogs, turtles, birds, mammals, an enormous diversity, plant impressions and the pollen released by those plants millions of years ago," said the researcher, who promised new discoveries that he does not want to reveal yet.

The first signs of the site were documented in 1980 by Argentine geologist Francisco Nulo, but the first exploration by palaeontologists was in 2019 by the team led by Novas.

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by Liliana Samuel, AFP


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